Wind turbine blades known in the art are typically made of wood or a mold material, such as fiber-glass or carbon fibers. Such wind turbine blades are typically manufactured in halves. The blade halves are manufactured by molding each half of a blade in a respective mold (or mold half). The two molded blade halves are connected to each other by putting them on top of each other, while they are still in the respective molds. Thus, there is a risk that a blade half in the mold which is rotated to be put on top on the other mold could fall out of the rotated mold or could at least be displaced in the mold.
For example, from EP 1 695 813 B1 it is known to fixate a blade half in a mold by providing the blade half with a curved fixating portion which engages a respective protrusion on the mold.
Moreover, from U.S. Pat. No. 6,264,877 B1 it is known to manufacture a blade in two halves by forming each half with a composite material formed in a respective first and second mold. The first mold is designed to be shut down on the second mold. The composite material formed in the first mold is covered with a film and a suction is established between the inside wall of the first mold and the film, thereby holding the composite material and the film against the inside wall of the first mold. Moreover, an inflatable envelope or balloon is placed on the composite material of the second mold. When the first mold is closed down to the second mold, the envelope is inflated to keep the composite material placed inside the first and second molds.
Although the fixing of the blade half as known from EP 1 695 813 B1 may provide a satisfactory fixating of the blade half, aspects of the present invention provide improved fixating of a wind turbine blade to a mold during manufacturing of the same.